A method for producing polyester fdy yarn

Abstract

The present application belongs to the technical field of polyester production, and relates to a production method of polyester FDY yarn. In the spinning process, a networker is used to add network to the yarn between a second heat box and a winding roller, and a tensioning guide rod is used to apply friction to the yarn between the second heat box and the networker, so as to offset part of the tension of the yarn, and further reduce the network pressure during network adding. The present application reduces the network air pressure and air consumption during the production of polyester FDY yarn while ensuring the product quality.

Description

Technical Field

[0001] This invention belongs to the field of polyester production technology and relates to a method for producing polyester FDY yarn. Background Technology

[0002] Polyester is the commercial name for polyester fiber in my country, and it is an important type of synthetic fiber. It is mainly produced from terephthalic acid (PTA) or dimethyl terephthalate (DMT) and ethylene glycol (EG) as raw materials, through esterification or transesterification and polycondensation reactions to obtain the fiber-forming polymer—polyethylene terephthalate (PET). This PET fiber is then spun and post-treated to produce fibers. Due to its advantages such as high modulus, high strength, good shape retention, and good barrier properties, PET fiber (polyester fiber) is widely used in apparel and industrial applications.

[0003] However, with continuous social development, the profit margin of ordinary polyester fiber is gradually shrinking, making energy conservation and consumption reduction a crucial aspect of production control. In the production process of polyester FDY (fully drawn yarn), web processing is a key step, enhancing the cohesion and stability of the yarn bundle by forming cross nodes on it. However, in existing technologies (such as patent CN110106582A), the FDY main web is typically added between the second roller and the winding roller. During this process, due to the relatively high yarn bundle tension (usually around 25g), the web air pressure must also be increased accordingly to meet the web-addition requirements. However, excessively high web air pressure not only increases air consumption and production costs but may also trigger a series of problems.

[0004] Specifically, increased network pressure leads to greater entanglement between monofilaments. While this can improve fiber bundling performance to some extent, excessive network pressure can cause fibers to break, resulting in fuzz (broken monofilaments). Fuzz directly reduces the mechanical properties of the fibers, affecting product quality and lifespan. Furthermore, excessive network pressure can cause severe oil splashing, further increasing energy consumption and costs during production. Simultaneously, excessive network pressure can also affect fiber uniformity, directly impacting the quality of the final product.

[0005] Therefore, how to reduce the network air pressure and air consumption during the production of polyester FDY yarn while ensuring product quality has become an urgent technical problem to be solved. Summary of the Invention

[0006] The purpose of this invention is to solve the problems existing in the prior art and provide a method for producing polyester FDY yarn.

[0007] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0008] A method for producing polyester FDY yarn involves using a web-forming device to web the yarn bundle located between a second heating box and a winding roller during the spinning process. A tensioning guide bar is also used to apply frictional force to the yarn bundle located between the second heating box and the web-forming device to counteract some of the tension on the yarn bundle, thereby reducing the web-forming pressure during web formation.

[0009] As a preferred technical solution:

[0010] The production method of polyester FDY yarn as described above has the following overall process flow: melt extrusion → cooling → oiling → heating in the first hot box → heating in the second hot box → tensioning the guide bar → adding a network in the networker → winding on the winding roller. The first hot box is equipped with a first splitting roller SR1 and a first hot roller GR1, and the second hot box is equipped with a second splitting roller SR2 and a second hot roller GR2.

[0011] In the above-described method for producing polyester FDY yarn, the single-hole flow rate during melt extrusion is 0.005-0.02 g / s, the cooling is achieved by side-blowing cooling, the cooling air temperature is 23-27℃, the cooling air velocity is 0.3-0.6 m / s, the temperature of the first hot box is 80-93℃, the temperature of the second hot box is 120-134℃, the rotation speed of the first hot roller GR1 is 1400-1800 m / min, the rotation speed of the second hot roller GR2 is 3845-5070 m / min, and the rotation speed of the winding roller is 3800-5300 m / min.

[0012] The method for producing polyester FDY yarn as described above includes a tensioning guide rod comprising an upper screw, a cylindrical bar, a lower screw, an upper guide disc, an upper nut, a lower guide disc, a lower nut, an aluminum tube, an upper guide device, a lower guide device, and a fixing frame.

[0013] The upper screw, cylindrical bar, and lower screw are coaxial and fixedly connected from top to bottom;

[0014] The upper screw passes through the center of the upper guide plate and the upper nut from bottom to top, and the lower screw passes through the center of the lower guide plate and the lower nut from top to bottom;

[0015] An aluminum tube is fitted onto a cylindrical rod and located between an upper guide wire disc and a lower guide wire disc. The outer diameters of the upper and lower guide wire discs are greater than or equal to the diameter of the cylindrical rod and less than the outer diameter of the aluminum tube.

[0016] There are multiple upper wire guides distributed at the edge of the upper wire guide plate, and multiple lower wire guides distributed at the edge of the lower wire guide plate;

[0017] The fixing frame is a U-shaped frame, with one end fixedly connected to the upper screw and the other end fixedly connected to the aluminum tube;

[0018] The filament bundle first passes through the upper guide wire and spirally winds around the aluminum tube, then exits from the lower guide wire.

[0019] The production method of polyester FDY yarn described above uses an aluminum tube with a length of 15-20cm, an outer diameter of 40-50mm, and a surface roughness of 0.2-0.7.

[0020] In the production method of polyester FDY yarn described above, the length L of the yarn bundle wound on the aluminum tube is 77-372 mm.

[0021] In the production method of polyester FDY yarn described above, the tension of the yarn bundle at the inlet of the networker is 3-15 cN, and the network pressure during network application is 2-3 bar.

[0022] The production method of polyester FDY yarn described above has a linear density of 30-167 dtex, a network density of 6-20 loops / meter, and a total number of end face fuzz and loops of 0-3.

[0023] Beneficial effects:

[0024] This invention addresses a series of problems caused by excessively high network air pressure in the existing polyester FDY yarn production process. By adding a tensioning guide bar between the second heating box and the networker, friction is applied to the yarn bundle, effectively offsetting some of the tension on the yarn bundle and thus significantly reducing the network pressure during network application. This improvement not only reduces air consumption and production costs but also effectively avoids problems such as fuzzing, oil splashing, and decreased fiber uniformity caused by excessive network pressure. Therefore, while ensuring product quality, it improves the production efficiency and economic benefits of polyester FDY yarn. Attached Figure Description

[0025] Figure 1 This is a schematic diagram showing the wire bundle passing through the tensioning guide bar and the mesh device in sequence; where 1-wire bundle, 2-upper guide bar, 3-upper guide plate, 5-fixed frame, 6-aluminum tube, 7-lower guide plate, 8-lower guide bar, 9-mesh device, 12-lower nut, 13-upper screw, 14-upper nut.

[0026] Figure 2 This is a schematic diagram of the overall process flow of the production method of polyester FDY yarn of the present invention; wherein, SR1 is the first yarn splitting roller, GR1 is the first hot roller, SR2 is the second yarn splitting roller, and GR2 is the second hot roller. Detailed Implementation

[0027] The present invention will be further described below with reference to specific embodiments. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. Furthermore, it should be understood that after reading the teachings of this invention, those skilled in the art can make various alterations or modifications to the invention, and these equivalent forms also fall within the scope defined by the appended claims.

[0028] like Figure 1 As shown, the tensioning guide rod in the following embodiments includes an upper screw 13, a cylindrical rod, a lower screw, an upper guide plate 3, an upper nut 14, a lower guide plate 7, a lower nut 12, an aluminum tube 6, an upper guide device 2, a lower guide device 8, and a fixing frame 5.

[0029] The upper screw 13, the cylindrical bar, and the lower screw are coaxial and fixedly connected from top to bottom;

[0030] The upper screw 13 passes through the center of the upper guide wire disc 3 and the upper nut 14 from bottom to top, and the lower screw passes through the center of the lower guide wire disc 7 and the lower nut 12 from top to bottom;

[0031] The aluminum tube 6 is fitted on the cylindrical rod and located between the upper guide wire disc 3 and the lower guide wire disc 7. The outer diameters of the upper guide wire disc 3 and the lower guide wire disc 7 are greater than or equal to the diameter of the cylindrical rod and less than the outer diameter of the aluminum tube 6.

[0032] There are multiple upper wire guides 2, which are distributed at the edge of the upper wire guide disk 3, and multiple lower wire guides 8, which are distributed at the edge of the lower wire guide disk 7.

[0033] The fixing frame 5 is a U-shaped frame, with one end fixedly connected to the upper screw 13 and the other end fixedly connected to the aluminum tube 6;

[0034] When spinning using this tensioning guide bar, the filament bundle 1 first passes through the upper guide 2 and spirally winds around the aluminum tube 6, and then exits from the lower guide 8. During the spinning process, the upper guide disc 3 and the lower guide disc 7 can be rotated (at this time, the upper screw 13 and the upper nut 14, and the lower screw and the lower nut 12 are in a loose state) to adjust the relative position of the upper guide 2 and the lower guide 8, thereby controlling the spiral degree of the filament bundle 1 on the aluminum tube 6. This not only helps with heat dissipation, but also effectively controls and reduces the tension of the filament bundle 1 at the inlet of the mesh 9. After the relative position of the upper guide 2 and the lower guide 8 is adjusted, the upper screw 13 and the upper nut 14, and the lower screw and the lower nut 12 are tightened at the same time, so that the upper guide disc 3 and the lower guide disc 7 are fixed on the cylindrical bar respectively.

[0035] The following are the test methods for the relevant performance indicators in each embodiment and comparative example:

[0036] Linear density: determined according to GB / T14343-2008 standard; wherein the test temperature is 25℃, the test humidity is 65%, and the pre-tension is 0.2cN / dtex.

[0037] Network density: The network density was measured using a filament network density tester (manufacturer: Changzhou Bafang Lishi Textile Instrument Co., Ltd., model BF1801); the test length was 1m, the test speed was 2.5m / min, the release force was 0.3cN / dtex, and the pretension was 0.1cN / dtex.

[0038] Total number of end face fuzz and loops: Inspectors use a flashlight to inspect the end face of the FDY yarn (7.5 kg in weight, 86 mm in width). Loops less than 3 mm in length are ignored, and loops ≥ 3 mm in length are counted. The total number of end face fuzz and loops is then tallied.

[0039] Example 1

[0040] A method for producing polyester FDY yarn, such as Figure 2 As shown, the overall process flow is as follows: melt extrusion of the spinning box → side blowing cooling → oiling → heating of the first hot box → heating of the second hot box → tensioning of the guide bar → adding network with the networker → winding of the winding roller;

[0041] Among them, the parameters related to the tensioning guide rod are: the length of the aluminum tube is 15cm, the outer diameter is 40mm, and the surface roughness is 0.2; the length L of the wire bundle wrapped on the aluminum tube is 77mm.

[0042] Process parameters: The single-hole flow rate during melt extrusion is 0.005 g / s, the cooling air temperature is 23℃, the cooling air velocity is 0.35 m / s, the temperature of the first hot box is 80℃, the temperature of the second hot box is 130℃, the rotation speed of GR1 is 1400 m / min, the rotation speed of GR2 is 4140 m / min, and the rotation speed of the winding roller is 4100 m / min.

[0043] Tests showed that the tension of the filament bundle at the inlet of the networker was 3cN, and the network pressure when the network was applied was 2 bar; the final polyester FDY yarn produced had a specification of 30dtex / 24f, a network density of 20 strands / meter, and a total of 0 end face fuzz and loops.

[0044] Comparative Example 1

[0045] A method for producing polyester FDY yarn is basically the same as in Example 1, except that a tensioning guide bar is not used.

[0046] Tests showed that the tension of the filament bundle at the inlet of the networker was 7 cN, and the network pressure when the network was added was 3.5 bar; the final polyester FDY filament had a network density of 16 per meter, and a total of 4 end face filaments and loops.

[0047] Compared with Comparative Example 1 and Example 1, the tension of the filament bundle at the inlet of the web maker, the web maker pressure during web application, and the total number of fuzzy and looped fibers in the polyester FDY filament were significantly increased, while the web filament density of the polyester FDY filament was significantly reduced. This is because without the use of a tensioning guide bar, the tension of the filament bundle cannot be effectively controlled, resulting in increased tension of the filament bundle at the inlet of the web maker. Higher filament bundle tension requires higher web maker pressure to meet processing requirements. Excessive web maker pressure can easily cause fibers to break, resulting in fuzzy fibers and an increase in the total number of fuzzy and looped fibers. At the same time, excessive web maker pressure can also affect the uniformity of the fibers, thereby reducing the web filament density.

[0048] Example 2

[0049] A method for producing polyester FDY yarn, such as Figure 2 As shown, the overall process flow is as follows: melt extrusion of the spinning box → side blowing cooling → oiling → heating of the first hot box → heating of the second hot box → tensioning of the guide bar → adding network with the networker → winding of the winding roller;

[0050] Among them, the parameters related to the tensioning guide rod are: the length of the aluminum tube is 16cm, the outer diameter is 42mm, and the surface roughness is 0.4; the length L of the wire bundle wound on the aluminum tube is 150mm.

[0051] Process parameters: The single-hole flow rate during melt extrusion is 0.007 g / s, the cooling air temperature is 25℃, the cooling air velocity is 0.3 m / s, the temperature of the first hot box is 82℃, the temperature of the second hot box is 120℃, the rotation speed of GR1 is 1426 m / min, the rotation speed of GR2 is 3845 m / min, and the rotation speed of the winding roller is 3800 m / min.

[0052] Tests showed that the tension of the filament bundle at the inlet of the networker was 7 cN, and the network pressure when the network was applied was 2.2 bar. The final polyester FDY yarn produced had a specification of 55 dtex / 72f, a network density of 15 loops / meter, and a total of 3 end face filaments and loops.

[0053] Example 3

[0054] A method for producing polyester FDY yarn, such as Figure 2 As shown, the overall process flow is as follows: melt extrusion of the spinning box → side blowing cooling → oiling → heating of the first hot box → heating of the second hot box → tensioning of the guide bar → adding network with the networker → winding of the winding roller;

[0055] Among them, the parameters related to the tensioning guide rod are: the length of the aluminum tube is 17cm, the outer diameter is 46mm, and the surface roughness is 0.5; the length L of the wire bundle wrapped on the aluminum tube is 200mm.

[0056] Process parameters: Single-hole flow rate during melt extrusion is 0.01 g / s, cooling air temperature is 25℃, cooling air velocity is 0.4 m / s, temperature of the first hot box is 82℃, temperature of the second hot box is 131℃, rotation speed of GR1 is 1650 m / min, rotation speed of GR2 is 4755 m / min, and rotation speed of the winding roller is 4700 m / min.

[0057] Tests showed that the tension of the filament bundle at the inlet of the networker was 10 cN, and the network pressure when the network was applied was 2.4 bar. The final polyester FDY yarn produced had a specification of 75 dtex / 24f, a network density of 13 loops / meter, and a total of 1 end face fuzz and loop.

[0058] Example 4

[0059] A method for producing polyester FDY yarn, such as Figure 2 As shown, the overall process flow is as follows: melt extrusion of the spinning box → side blowing cooling → oiling → heating of the first hot box → heating of the second hot box → tensioning of the guide bar → adding network with the networker → winding of the winding roller;

[0060] Among them, the parameters related to the tensioning guide rod are: the length of the aluminum tube is 18cm, the outer diameter is 48mm, and the surface roughness is 0.6; the length L of the wire bundle wrapped on the aluminum tube is 280mm.

[0061] Process parameters: The single-hole flow rate during melt extrusion is 0.015 g / s, the cooling air temperature is 26℃, the cooling air velocity is 0.45 m / s, the temperature of the first hot box is 92℃, the temperature of the second hot box is 133℃, the rotation speed of GR1 is 1800 m / min, the rotation speed of GR2 is 5070 m / min, and the rotation speed of the winding roller is 5300 m / min.

[0062] Tests showed that the tension of the filament bundle at the inlet of the networker was 12 cN, and the network pressure when the network was applied was 2.8 bar. The final polyester FDY yarn produced had a specification of 111 dtex / 36f, a network density of 9 loops / meter, and a total of 1 end face filament and loop.

[0063] Example 5

[0064] A method for producing polyester FDY yarn, such as Figure 2 As shown, the overall process flow is as follows: melt extrusion of the spinning box → side blowing cooling → oiling → heating of the first hot box → heating of the second hot box → tensioning of the guide bar → adding network with the networker → winding of the winding roller;

[0065] Among them, the parameters related to the tensioning guide rod are: the length of the aluminum tube is 20cm, the outer diameter is 50mm, and the surface roughness is 0.7; the length L of the wire bundle wrapped on the aluminum tube is 372mm.

[0066] Process parameters: Single-hole flow rate during melt extrusion is 0.02 g / s, cooling air temperature is 27℃, cooling air velocity is 0.6 m / s, temperature of the first hot box is 93℃, temperature of the second hot box is 134℃, rotation speed of GR1 is 1670 m / min, rotation speed of GR2 is 4350 m / min, and rotation speed of the winding roller is 4300 m / min.

[0067] Tests showed that the tension of the filament bundle at the inlet of the networker was 15 cN, and the network pressure when the network was applied was 3 bar. The final polyester FDY yarn produced had a specification of 167 dtex / 96f, a network density of 6 loops / meter, and a total of 2 end face filaments and loops.

Claims

1. A method for producing polyester FDY yarn, in which a networker is used to network the yarn bundle between a second heat box and a winding roller in the spinning process, characterized in that, The tensioning guide rod is used to apply friction force to the yarn between the second heat box and the networker to offset part of the tension of the yarn, thereby reducing the network pressure during network adding.

2. The method of producing polyester FDY yarn according to claim 1, wherein, The overall process flow is: melt extrusion→cooling→oiling→first heat box heating→second heat box heating→tensioning guide rod→networker network adding→winding roller winding, wherein the first heat box is provided with a first yarn separating roller SR1 and a first heat roller GR1, and the second heat box is provided with a second yarn separating roller SR2 and a second heat roller GR2.

3. The method of producing polyester FDY yarn according to claim 2, wherein, The single-hole flow during melt extrusion is 0.005-0.02 g / s, the cooling is performed by side blowing cooling, the cooling air temperature is 23-27℃, the cooling air speed is 0.3-0.6 m / s, the temperature of the first heat box is 80-93℃, the temperature of the second heat box is 120-134℃, the rotating speed of the first heat roller GR1 is 1400-1800 m / min, the rotating speed of the second heat roller GR2 is 3845-5070 m / min, and the rotating speed of the winding roller is 3800-5300 m / min.

4. The method of producing polyester FDY yarn according to claim 2, wherein, The tensioning guide rod comprises an upper screw rod, a cylindrical rod, a lower screw rod, an upper godet, an upper nut, a lower godet, a lower nut, an aluminum pipe, an upper yarn guide, a lower yarn guide, and a fixing frame; The upper screw rod, the cylindrical rod, and the lower screw rod are coaxial and are sequentially fixed and connected from top to bottom; The upper screw rod sequentially passes through the center of the upper godet and the upper nut from bottom to top, and the lower screw rod sequentially passes through the center of the lower godet and the lower nut from top to bottom; The aluminum pipe is sleeved on the cylindrical rod and located between the upper godet and the lower godet, the outer diameter of the upper godet and the lower godet is greater than or equal to the diameter of the cylindrical rod and less than the outer diameter of the aluminum pipe; The number of the upper yarn guides is multiple and is distributed at the edge of the upper godet, and the number of the lower yarn guides is multiple and is distributed at the edge of the lower godet; The fixing frame is a U-shaped frame, one end of which is fixedly connected with the upper screw rod, and the other end of which is fixedly connected with the aluminum pipe; The yarn is first spirally wound on the aluminum pipe through the upper yarn guides and then passes out from the lower yarn guides.

5. The method of producing polyester FDY yarn according to claim 4, wherein, The length of the aluminum pipe is 15-20 cm, the outer diameter is 40-50 mm, and the surface roughness is 0.2-0.

7.

6. The method of producing polyester FDY yarn according to claim 5, wherein, The length L of the yarn wound on the aluminum pipe is 77-372 mm.

7. The method of producing polyester FDY yarn according to claim 6, wherein, The tension of the yarn at the inlet of the networker is 3-15 cN, and the network pressure during network adding is 2-3 bar.

8. The method of producing polyester FDY yarn according to claim 7, wherein, The linear density of the polyester FDY yarn is 30-167 dtex, the network degree is 6-20 / m, and the total number of end face fluff and loop yarn is 0-3.

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